Electrical apparatus



| A. M. PHELAN EI AL Sept. 7 1926.

ELECTRICAL APPARATUS Filed Dec. 22', 1922 lii Patented Sept. 7 1926.

UNITED STATES PATENT; oFFm LOUIS A. 1!. runner AND ram; 1:.

CBAMBLE'I, OI BELOIT, WISCONSIN.

nnacrnrdar. Arrmrus.

Application filed December 22, 1922; Serial No. 608,504.

' Our invention relates to electrical appa-- ratus and it has specialreference to improvements in electrical contact-making devicescomprising spaced electrodes that are sealed into a closed container andare adapted to be brought into electrical conducting relation with oneanother through the agency of a movable conducting body, preferably afluid such as mercury, likewise disposed in said" container and which,on being tilted, is instrumental in performing the circuit-closing andcircuit-opening functions of the device. Our invention may comprise aflat elon-' gatedcontainer preferably in the form of a glass tube thatserves to enclose a pair of co-operatin'g electrodes and a body ofconducting liquid, such as mercury, the latter being adapted to bridgethe electrodes within the tube. The tube is preferably disposed wheninstalled to occupy normally a position neighboring on the horizontaland is intended to besuitably supported so that it may be tilted at theexpense of'very little energy in order to bring the conducting liquidinto and out of bridging relation with. the electrodes.

within the tube and as shown in this particular instance, the ends ofthe electrodes which The electrodes are sealed are bridged by the bodyof conducting fluid are located adjacent one end of the tube.

A. particular object of our present form of construction is to provide acontainer tube of such shape that it will serve to guide the conductingfluid in a definite channel. Such a construction. is for the pur oseof'avoiding accidental contacting o the mercury with the electrodes dueto splashing or other undesired movements of thebody. of mercury.

Another object of our invention is'to provide an efiicient and verysimple form of electrode structure. 7

A 'furtherobject of our invention is to provide .a contactor deviceofthe type indicated that will be economical to construct and which willpossess a long'life even when subjected to serious mechanical abuse.

erence to the following description. and ac of the tube 1 and serve tobring the current through the glass walls of this companying drawings,in which' lgure 1 1s a vertical sectional vlew of one modification ofdevice embodying our invention;

Fig. 2 is an end view of the dev ce shown Fig. 3 is aplan view ofdevice;

F 4 is an enlarged detail view, partly in section showing theconstruction of the electrodes;

Figs. 5, 6, 7 and 8 are detailed cross-sectional views showing variouspossible modifications in the shape of the container.

'The above described views, with the except1on of F 4, for clearnessillustrate the invention in approximatelytwice its natural size; It maybe here noted that the size of the container is an importantconsideration in its design because of the and surface tensionproperties of the body of mercury.

.The device as shown comprises -in a general Way acontainer 1 preferablyformed of glass or a like material, electrodes 2 and 3 sealed andsupported in the interior of the container tube 1 and a body ofconducting fluid, such as mercury 4, which is free to peculiar capillaryflow along the bottom of the interior of the the various parts and toselect the proper materials. It is preferable that the mercury 4besubstantially free from impurities of all kinds. The electrodes 2 and 3are preferably constructed of a pure metal, such as iron, which is notchemically affected by the mercury in the presence of the extremetemperatures of electrical arcs which may occur at the electrodes. Theinterior of the tube 1'" is preferably evacuated and filled witha gaswhich does not combine in any way with the metal of the electrodes 2 and3, or with the mercury in the presence of the intense heat. Hydrogen atsubstantially atmospheric pressure has been found to be satisfactory forthis purpose. The tube .1 is evacuated and filled with the inert gas andsealed off at a tip 5. i

The electrodes 2 and 3 may be\formed at the ends of thin. cylindricalsleeves 6 and 7,

respectively, formed of a metal such as pure iron. The sleeves 6 and *7are supported upon and serve to encase the inwardly extending ends ofleading-in wires 8 and 9, respectively, which pass through the wallstube without the possibility of any leakage of gas .in or out 'of thetube at this point. Dumet wire 'ispreferably usedfor no I these leadingin wires because of its desir-- able expansive.=properties when sealedin V glass. The sleeves 6 and 7 are extended for a slight distance alongthe leading-in wires 8 and 9, respectively, into the glass structure andthus serve to protect completely the Dumet Wire from exposure to theintense heat and gases within the tube 1.

Glass shanks 10 and 11 are formed on the walls of the tube 1 at a pointwhere the wires 8 and 9, respectively, are sealed. These shanks serve tosupport securely the electrodes 2 and 3 and provide for an extendedsealing area between the wires 8 and 9 and the glass of the tube 1. Itwill be further noted that the glass shanks 10 and 11 are located at theends of and at the upper side of the tube 1 so that they are remote fromthe body of mercury 4 and from any arcing that may occur at electrodes 2and 3. Thus the possibility of injury by heat to the sealed portions ofthe wires '8 and 9 is avoided.

The sleeves 6 and 7 are flattened at their ends in order to formelectrodes 2 and 3 and also in order to close their ends against accessof the mercury or gas within the tube 1. It will be noted that as shown,the electrode 3 is flattened in a direction parallel to the axis of thetube 1 and consequently parallel to the direction of the flow of thebody of mercury 4. The electrode'3' is also placed in an inclinedposition in respect to the body of mercury 4:. The advantage of thisparticular form of flattened inclined electrode is to enable theelectrode to offer as little resistance as possible to the movement ofthe body of mercury 4 and to still retain a large contact area with themercury. The resistance to the movement of the mercury into and out ofcircuit-making;

position is a very important consideration in the construction ofcontactors of this character, which are-designed to operate when tiltedto only a 'very slight angle. In

such cases the .flow of mercury can be very easily checked or entirelyprevented.

By reference to Figs. 2 and 5, it will be noted that the tube is shownwith-a pronounced flattened cross section. With this design of the crosssection of thetube, it will be noted that sides 12 and l3,extend upvertically for a considerable distance in contact with the sides of thebody of mercury 4 and thus serve to form a channel which guides themercury and serves to prevent any splashing or undesirable movements ofthe liquid. When the mercury flows in the channel of this type, its.depth and stability can be much more easily con trolled than whenthe'm'ercury is placed in the usual tube of circular cross section, suchfor example as indicated in Fig. ,8. With the shape of tube shown inFig. 2, practically all movement of the mercury is limited to that in adirection parallel to the axis of the tube, which is the .only'direction of movementwhich is essential for the proper action of thecontactor.

In certain instances it is desirable to use a contactor of this typewhich will actuate upon being tilted only a small number of degrees fromthe horizontal. In such cases, it is desirable to eliminate as much ofthe frictional effect as possible between the moving body of .mercuryand the container walls. It has been found that expedients such as shownin Fig. 5 for stabilizing the mercury also have a slight tendency toretard the free 'fiowing of the mercury even along its intended path.Accordingly it has been found to be advisable to modify thecross-sectional shape of the container in order to secure the mostdesirable results under different tilting angles and stabilizationrequirements. In other words, it is desirable to stabilize the mercuryas much as possible without rendering its action too sluggish.

It has been found that mercury flows very freely upon a horizontal fiatsurface. The design shown in Fig. 6 makes use of this fact since thelower side of the tube is formed as a fiat surface upon which themercury flows or rolls withconsiderably more freedom than on the roundedsurface shown in Fig. 5. The vertical parallel side walls forstabilizing the mercury are retained in Fig. 6 as in Figs. 2 and 5.Figs. 7 and 8 show forms of cross-sections which respectively tend topermit still greater freedom' and less stabilization of the mercury thando the above described structures.

As shown in Fig. 2, it is preferable to space the fiat side walls of thecontainer at an appreciable distance apart in order to preventunnecessary sluggishness of the mercury as when too closely confined. Itwill be further noted that considerable space at the upper side of thecontainer is shown into which the mercury does not extend. This ampleamount of space permits the placing of the electrode leads andsupporting shanks in a position where they will not interfere with thefree flowing of the mercury when in its proper channel. Furthermore, thetop wall as shown is at a sufficient distance from the bottom wall toprevent the cooperation of these walls with the other walls of thecontainer in holding or restraining the body of mercury, incaseinterpreted and limited only art and by the scope of the appendedclaims. r c

What we claim as new and 'desire to secure by Letters Patent of the U.S. is 1. An electrode for contacting with a movable body of conductingliquid, com-- a tubular shell flattened at its end rection parallel'tothe movement of prisilzigJ said body of conducting liquid. q 2. In anelectrical device, the combination of a supporting wire, and a tubularprotecting shell surrounding said wire, an

end of said shell extending beyond said wire container, a movable bodyand being crushed to close said shell and to form an electrode.

3. An electrical device comprising a con tainer, a movable body ofconducting liquid in said container, and electrodes in said container inthe ath of said movable body of liquid, said e ectrodes being formed oftubular shells, the ends of which are-crushed to close said shells.

4. An electrical contactor comprising a of conducting liquid in saidcontainer, and electrodes in said container in the path of said movablebody of liquid, one of said electrodes being ment of said body ofliquid.

formed of a tubular shell flattened in a direction parallel to thedirection of move- 5. An electricalcontactor comprising a container, amovable body of conducting liquid in said container, and electrodes insaid container in the path of said movable bodyof liquid, one of saidelectrodes being flattened in a direction parallel to the direction ofmovement of said body of liquid.

6. An electrical contactor comprising a container, a movable body ofconducting liquid in. said container, and electrodes in said containerin the path of said movable body of liquid, one of said electrodes beingflattened in a direction parallel to the direction of movement of saidbody of liquid and Lpositioned in an inclined relation with re-- spectto the surfaceof said bodyof liquid. 7. An electrical contactorcomprising a container, a movable body of conducting liquid in saidcontainer, and electrodes in said container in the ath of said movablebody of liquid, one of said electrodes having much the larger portion ofits surface contact area extending in directions sub stantially parallelto the direction of move ment of said body of liquid.

In witness whereof, we have hereunto subscribed our names.

' LOUIS A. M. PHELAN. PAUL K. CRAMBLET.

